Components myofibril

Question 1

Fibers are long and cylindrical, Are huge cells– diameter is 10–100µm, Length– several centimeters to dozens of centimeters

Answer 1

Skeletal muscle fiber

Question 1

Each cell formed by fusion of embryonic cells is called

Answer 1

Mysoblast

Question 2

Cells are multinucleate, Nuclei are peripherally located

Answer 2

Skeletal muscle fiber

Question 3

Long rods within cytoplasm, Make up 80% of the cytoplasm, Are a specialized contractile organelle found in muscle
tissue

Answer 3

Myofibrils

Question 4

A long row of repeating segments called _________

Answer 4

Sacromeres

Question 5

boundaries of each sarcomere

Answer 5

Z disc or line

Question 6

run the entire length of an A band

Answer 6

Thick filaments

Question 7

run the length of the I band and
partway into the A band

Answer 7

Thin filaments

Question 8

coin-shaped sheet of proteins that anchors the thin filaments and connects myofibrils to one another

Answer 8

Z disc

Question 9

lighter midregion where filaments do not overlap.

Answer 9

H-Zone

Question 10

line of protein myomesin that holds adjacent thick filaments together

Answer 10

M-Line

Question 11

2 interwoven, heavy polypeptide chains

Answer 11

Myosin tails

Question 12

2 smaller, light polypeptide chains that act as cross bridges during contraction

Answer 12

Myosin heads

Question 13

a spring-like molecule in sarcomeres

Answer 13

Titin

Question 14

A calcium regulated protein in muscle tissue occurring in three subunits with tropomyosin

Answer 14

Troponin

Question 15

Any of a group of muscle proteins that bind to molecules of actin and troponin to regulate the interaction of actin and myosin

Answer 15

Tropomyosin

Question 16

Functions in the regulation of intracellular Ca2+
levels

Answer 16

Sarcoplasmic reticulum

Question 17

Continuous with the sarcolemma

Answer 17

T tubules

Question 18

Network of smooth endoplasmic reticulum
surrounding each myofibril

Answer 18

Sarcoplasmic reticulum

Question 19

Pairs of terminal cisternae form perpendicular cross channels

Answer 19

Sarcoplasmic reticulum

Question 20

Penetrate the cell’s interior at each A band–I band
junction

Answer 20

T tubules

Question 21

Associate with the paired terminal cisternae to form
triads that encircle each sarcomere

Answer 21

T tubules